First-principles study of the influence of the chlorine, oxide, and sulfur impurities on the grain boundary strength in aluminium and copper

Computational Condensed Matter. 2026. Vol. 47. Article e01295.

Корзникова Е. А., Mukhametov A., Samikov I., Kistanov A. A.

Aluminium (Al)- and copper (Cu)-based alloys may corrode in harsh environments. This occurs because corrosion ions penetrate into the intergranular structures and react with the atoms of the host matrix at the grain boundaries (GBs). Therefore, elucidating atomic-level mechanisms at GBs is critical for enhancing Al/Cu corrosion resistance upon penetration of corrosion ions, such as Cl, O, and S. In this study, first-principles simulations were utilized to evaluate the impact of corrosion ions on the strength of Σ3(111) coherent twin, Σ3(112) incoherent twin, and high-angle Σ5(0 2 1) GBs in Al and Cu. It is found that all the considered corrosion ions act as a detrimental impurity, segregating at Al and Cu GBs and causing embrittlement. Meanwhile, GB's embrittlement by corrosion ions is driven by mechanical strain, caused by atomic displacements and chemical effects caused by bond alteration. Chloride ions have a more aggressive effect on brittleness of Al and Cu than O ions. This study uncovers the mechanism of the corrosion ions effect on the GB strength in Al and Cu and also provides valuable information for developing an effective strategy for their protection against corrosion.

Keywords: деградация, degradation, DFT, Metals, DFT, Harsh environment, Interstitial defect, Межкристаллитный дефект, Агрессивная среда, Металлы

Publication based on the results of: Analytical and computer simulation of wave energy transfer at different length scales (2025)